Boiler



Junev 4, 1935. T. B. sTlLLMAN 2,004,058

BoILER` Filed Aug., 19, 1932 3 Sheets-Sheet 2 lNVENTOR 7710111115 Sii/[mall ATTORNEY June 4, 1935. T. B. sTlLLMAN Boum* Filed Aug. u19, 1932 f Forster type.

Patented June 4, 1935 UNITED STATES- PATENT oFFicE BorLER Thomas B. Stillman, South Orange, N. J., as-

signor to The Babcock daV Wilcox Company, Bayonne, N. J., a corporation of New Jersey Application August 19, 1932, Serial No. A629,463

' 7 claims. (c1. 12a-+265) This invention relates to steam boilers of the water tube type, and, more particularly, to water tube boilers, which due to their capacity for high rates of evaporation, lightness and compactness of construction, are especiallyadapted for marine installations. l Y

One steam boiler construction embodying the above characteristics and which has Vgone into extensive'use is commonly known as theWhite- Boilers of this type are further characterized-by their capacity for the replacement of any of the tubes in the steam generating bank without disturbing any other tube; this property being attained by bending and position- Ting each of these tubessothat itis curved longitudinally` and laterally and slightly enlarging the` tube diameter at the steam and water drum end, allowing the tube to be withdrawn or installed through the drum manhole opening. In such boilers, the tubes in the upper section of the bank are curved longitudinally opposite to the curvature of the tubes in the lower section, thusleaving a space between the adjacent rows of tubes in the two sections. In attempting to adapt a boiler of this type to modern steam generating conditions, involving the production of highly rsuperheated steam, this space has been utilized as the location of a steam superheater. It has been found in practice that the amount of superheating surface capable of being incorporated in that location is extremely limited and cannot be increased without disadvantageously affecting the structural characteristics of the boiler.` This superheater location is further disadvantageous because the temperature of the heating gases is substantially reduced before it reaches the superheater. The small amount of superheating `surface present and the reduced heating gas temperature at that point jointly limit the degree of superheating obtainable to a value `below that required for the operation of modern steam utilizing Ydevices at high 'eiliciencies The general objectcof my invention is the provision of an inproved construction of a steam boiler of the Water tube type.

A further and more specific object is the provision of a `high capacity express type marine boiler having an improved construction and arrangement of steam superheating surface.

Another specific object is an improved proportioning and arrangement of steam generating, superheating, and feed water heating surface in a boiler o f the character described.

Another speciiic object is the provision of supporting means for a multiple tube bank steam boiler permitting' substantially free expansion and contraction of the tubes connecting the drums.

Another specicpbject is theprovision of an improved location and construction of an economizer in a boiler of the character described.

The various featuresof novelty which characterize my invention are pointed out with Vparticularity inthe claims annexed to and forming a part of this specicaton. For a better understanding of the invention, its operating'advantages andspecic objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which I have` illustrated and described a preferred `embodi.J ment of my invention.T Of the drawings-n j Fig. 1 is a sectional 'elevation ofra boiler of the White-Forster type, modified in accordance with my invention; Y ,Y Fig. 2 is a section ,on the 1ine2-2 of Fig. 1; Fig. 3 is a.v fragmentary View illustrating a modified leconomizer construction; f Fig. 4 .is 4afdetail partly Yin. section illustrating the connectionof the econornizer tubes to one of the headers; and u' Fig. 5 is a frontview of the structure shown in Fig.4. A

In the steam boiler illustrated in the drawings, the reference numeral i designates a horizontal steam and water drum of large diameter extendingalong and above one Wall of the `boiler setting I4. Below Yand laterally spaced from the drum l is a water drum 3 connected thereto 'oy a bank of steam generating tubes 2. Each of the tubes 2 is curved in two directions, as indicated in Figs. 1 `and 2 to permit itsreplacement through the manhole opening la at one end of the drum l without interfering with any other tube in the bank. The bank of tubes 2 is divided into upper and lower `sections 2at and 2b, respectively, the tubes in the two sections being oppositely curved in one direction. leaving a narrow space between their adjacent rows.

The space available between the sections of the tube bank has been found inadequate for the location of the amount of superheating surface required for the desired degree of superheat with heating gas Vtemperatures as at that point. The

offset chamber I3 formed in one of the side walls of the boiler and connected by nested rows of U- Y tubes III extending across the boiler with their return bend portions positioned in a similarly ofiset chamber I3a at the other side of the boiler. The chambers I3 and ISa, and headers IIand I2, extend parallel and adjacent to thelowermost row of'tubes 2. In the superheater construction shown, the header I I is divided at an intermediate point by a transverse partition II e into inlet and outlet chambers having steam inlet and outlet connections IIb and IIC, respectively, connected thereto. A conduit 55 connects the header inlet chamber to the steam and water drum I, while the outlet connection I I? leads to any steam utilizing device. The superheater tubes'are expanded into the headers II and i2 in clusters, and suitable handhole openings and closure devices are provided for allowing access to each tube cluster. The portion of the wall of thecham- Aber I3a opposite the return bend portionsr of the tubes is made removable to permit any of the superheater tubes to be replaced through the side of the boiler, rendering unnecessary the provision of space in the re room sufficient for the Vwithdrawal of the superheater as a unit.

Heat is supplied to the boiler by means of suitable fuel burners positioned in openings 40,. located in the boiler front wall below the drum I. High temperatures are normally maintained in the combustion chamber I5, and to avoid name impingement'on the superheater tubes, a relatively shallow bank of water tubes 6 is arranged between vthe superheater and the combustion chamber.y The tubes 6 are arranged parallel to the superheater headers andconnected attheir upper and lower ends, respectively, into horizontal drums 5 and l. The drum 5 extends below and slightly infront ofthe drum I, and has a supporting connection therefrom through a row of nipples 4. 'Ihedrum I is .positioned directly below theV drum 3 and connected thereby by nipples 8.

In operation, the tubes 2 and 6 tend to expand and contract in accordance with temperature variations. To permit expansion and contraction of the tubes without damage tofthe boiler'structure, the drum I is supported on posts 3l?, carrying yat their upper ends a saddle `3I.1 The drum l is likewise supported on saddles 35, and through the nipples 8 supports the drum 3 thereabove; With this arrangement .of the parts, each tube bank is xed at a different end and substantially free to expand and contract to or from the other end. The nipples #and 8 permit some lateral movement of each of the supported drums relative to the adjacent supporting drum. Some compensation for expansion and contraction is also attained by the curvature of the steam generating tubes.

An effective heat transfer is established in the boiler by proportioning the tube diameters and spacing to provide a successively increasing amount of heating surface in the pass through the superheater tubes I is slightly less than that of the remaining tubes in the bank 5, while the tubes 2 are more closely spaced than the tubes 6 and of less diameter than the superheater tubes.

The heatingrgases generated in the combustion chamber I successively Contact with the bank of tubes 6, the superheater, and the main bank of tubes 2, all being compactly arranged in a single gas pass. An economizer is advantageously incorporated in the boiler construction described, and as shown in Figs. l and 2, the economizer consists of superposed horizontal headers 5.2, 43, III and 45 arranged along one Vside wall of the boiler and serially connecting 'lower end and the adjacent portion of the drum I is closed by a complementary bailie 5I. The tubes 46 are preferably inclined to the vertical tothe same extent as the baille 48. The flow of heating gases to all portions of the economizer is facilitated .by an inclined distribution balile 52 mounted on the uppermost row of tubes 2 and extending upwardly Ymidway of the gas pass betweeny adjacent economiser tubes.

A relatively large amount of economiser surface can bel incorporated in the available space, which is usually of a heightV substantially the same as the diameter of the drum I, by swaging down the ends of :the economizer tubes, as shown in Fig. 4. The ,bodies of the tubes can therefore be closely spacedprovidinghigh heating gas velocities and high heat transfer rates. The swaged ends of the tubes are expanded in a .counterbored tube seat and the belled tube end welded aroundV its entire circumference to the header, asrindicated at 53. Hand holes 54 provide visibility for the expanding and Ywelding operations.

The intermediate headers 53 and Il are .con-3 nected at one end to provide a serial flow through the economizer sections. Wall baiiles 56 prevent short circuiting of the economizer surface, as

shown in Fig. 42. The spacesbetween the headersV tubes 6, and downward in the other tubes of the main bank. The steam generated passes from the drum I through a pipe 55 to the inlet chamber of the superheater.

The location of the fuel burners in the front wall of the boiler rather than in one of the side walls, Vreduces the amount of combustion chamber volume and overall boiler height required.

In this location, the boiler gauge glass 60 willY be directly in view of the operator in charge of the fuel burners. The specified proportioning of the heating surface over whichthe heating gases pass, provides equi-spaced paths for the heating gases, so that the heat ,input into the tubes ismore nearly uniform throughout their length. The generating capacity of the boiler will be quite high and its compactness and low weight make the design particularly desirable for 75I marine installations.

While in accordance with the provisions of the statutes I have illustrated and described herein the best form of my invention now known to me, those skilled in the art will understand that changes may be made in the form of the apparatus disclosed Without `departing from Vthe spirit of the invention covered by my claims, and that certain features of my invention may sometimes be used to advantage without a corresponding use of other features.

I claim:

1. A water tuberboiler comprising a combustion chamber, a horizontal steam and water drum of large diameter, a horizontal water drum spaced therefrom, an inclined bank of curved steam generating tubes connecting said drums, said tubes being curved in two directions, a second inclined bank of curved steam generating tubes in front of and spaced from said first bank, horizontal water drums connected to opposite ends of said second bank, a superheater positioned in the space between said tube banks, nipples connecting the drums at corresponding ends of said banks, and an economizer including return bend tubes extending transversely of and above said first bank, the tubes of i said superheater being of less diameter and more closely spaced than the tubes of said second bank, and the tubes of said first bank being of less diameter and more closely spaced than the tubes of said superheater.

2. A water tube boiler comprising a combustion chamber, a horizontal steam and water drum,

a horizontal water drum spaced therefrom, an inclined bank of curved steam generating tubes connecting said drums, a second inclined bank of curved steam generating tubes in front of and spaced from said first bank, horizontal water drums connected to opposite ends of said second bank, a superheater positioned in the space between said tube banks, nipples connecting the drums at corresponding ends of said banks', and an economizer` including return bend tubes extending transversely of and abovesaid first bank, the tubes of said superheater being of less diameter and more closely spaced than the tubes of said second bank, and the tubes of said first bank being of less diameter and more closely spaced than the tubes of said superheater.

3. A water tube boiler comprising a combustion chamber, a horizontal steam and water drum, a horizontal water drum spaced therefrom, an inclined bank of curved steam generating tubes connecting said drums, a second inclined bank of curved steam generating tubes in front of and spaced from said first bank, horizontal water drums connected to opposite ends of `said second bank, a superheater positioned in the space between said tube banks, means for supporting said steam and water drum of said first bank, means necting said drums, a second inclined bank of steam generating tubes belowV and spacedrfrom said first bank, horizontal water drums connected toi opposite ends of said second bank, means for supporting said steam and water drum of said first bank, means for supporting the water drum at the lower end of said second bank, and means for supporting the remaining drum of each bank from the supported drum at the corresponding Y end of the other bank.

5. A water tube boiler comprising a combustion chamber, a steam and water drum, a water drum spaced therefrom, a bank of` steam generating tubes connecting said drums, a second bank of steam generating tubesbelow and spaced from said first bank, Water drums connected to opposite ends of said second bank, means for supporting one of said drums of said first bank, means for supportingA the drum at the opposite endof said second bank, and means for'supporting the remaining drum of each bank from the supported drum at the corresponding end of the other bank.

6. A water tube boiler comprising a combustion chamber, a horizontal steam and `water drum of large diameter, a man-hole formed in one end of said drum, a horizontal water drum spaced therefrom, an inclined bank of curved steam generating tubes connecting said drums, said tubes being curved in two directions to permit their replacement through the man-hole of said steam and water drum, a second inclined bank of steam generating tubes in front of and spaced from said first bank, horizontal water drums connected to opposite ends of said second bank, and a superheater positioned in the space between said tube banks.

7. A Water tube boiler comprising a combustion chamber, a horizontal steam and water' drum of large diameter, a man-hole formed in one end of said drum, a horizontal water drum spaced therefrom, an inclined bank of curved steam generating tubes connecting said drums, said tubes being curved in two directions to permit their replacement through the man-hole of said steam andwater drum, a second inclined bank of curved steam generating tubes in front of and spaced from said first bank, horizontal water drums connected to opposite ends of ysaid second bank, a bank of superheater tubes positioned Vin the space between said tube banks, and nipples connecting the drums at corresponding ends of said Vtube banks. for supporting the water drum at the lower end THOMAS B. STILLMAN. 

